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Marshall Amplification is a British company which designs and manufactures electric guitar amplifiers. Marshall amplifiers are well known and highly popular among guitarists. The sight and sound of a Marshall stack amp with a Gibson Les Paul or Fender Stratocaster is an iconic image in pop culture. Marshall amps were originally built as direct copies of Fender amplifiers, but soon incorporated certain traits which made them more favorable to guitarists seeking a heavier sound.

Like most professional-level amplifiers, Marshall amplifiers still use valve preamp and poweramp stages instead of solid state devices (transistors), although Marshall also manufactures cheaper solid-state or hybrid devices.

Valve amplifiers (known as "tube amplifiers" in North America) are generally considered to exhibit a "warmer" tone than those of transistor amps, particularly when overdriven; instead of abruptly clipping off the signal at cut-off and saturation levels, the signal is smoothly rounded off. Vacuum tubes also exhibit different harmonic effects than transistors (see tube sound for more about the sonic differences between transistors and vacuum tubes). Though technology continues to change, the most sought after, best sounding, and most expensive amps use technology that is considered quite obsolete. The sound of a Marshall 1959SLP or JCM800 amp is among the most recognized in popular music, and there is a constant demand for both cutting edge and vintage amplifiers. They are now some of the most expensive amps on the market.

Contents 1 History 2 Current Models 2.1 Modern Series 2.2 Vintage Modern series 2.3 Vintage series 2.4 Solid State Amplifiers 2.5 Bass series 2.6 Model number confusion 3 The Marshall Legacy 4 Trivia 5 See also 6 References 7 External links

Jim Marshall first went into business in the early 1960s with a small shop in Hanwell, London, selling drums, cymbals and drum-related accessories; Marshall himself also gave drum lessons. According to Jim, Ritchie Blackmore, Pete Townshend and other guitarists frequently would come into the shop and ask why Marshall was not selling or producing guitar equipment. ^[1] Marshall Ltd. later expanded and started selling guitars and amplifiers, the most notable of which at the time were the Fender amplifiers imported from America. These were very popular with guitarists and bass players, but also very expensive, and Jim Marshall thought he could produce an equivalent product for less money. He enlisted the help of his shop repairman Ken Bran and an unknown EMI technician named Dudley Craven and between them they decided they most liked the sound of the 4x10" Fender Bassman. They made several copies similar to, but at the same time a bit different than the Fender. The sixth prototype was in Jim's words, the "Marshall Sound." [1] The first few production units were almost exactly the same as the Bassman circuit, with US-origin transformers and military surplus 5881 power valves. The first difference was the cabinet used, as Marshall decided to build separate amplifiers and speaker cabinets, and as they were originally intended as bass amplifiers, Marshall chose to use four 12 inch Celestion speakers in a closed back cabinet, instead of the Bassman's four 10 inch Jensen speakers in an open back cabinet. This new amplifier was named the JTM45 after Jim and his son Terry Marshall, and "45" as, in theory, it produced 45W of power.

In search of lower production costs, Marshall quickly started sourcing parts from the UK. This led to the use of Dagnall- and Drake-made transformers, and a switch to the Marconi-Osram Valve Company’s KT66 valve instead of the 6L6 tube commonly used in the United States. This gave Marshall amplifiers a more aggressive voice which quickly found favour with players, most notably a young Eric Clapton, who would sit in Jim's shop practicing his playing. When Clapton was invited to join John Mayall's Bluesbreakers, he asked Jim Marshall to produce a combo amp with tremolo which would fit in the boot of his car, and the most famous Marshall amp was born, the so called "Bluesbreaker" amp. [2] This is the amplifier that gave Clapton that famous tone on the Bluesbreaker's Beano album.

Other early customers included Pete Townshend and John Entwistle of The Who, whose search for extra volume led Marshall to design the classic 100 watt valve amplifier. After the creation of the full "stack," the competition for volume between the two drove Pete to request Jim to build him an amplifier with even more power. Jim Marshall was at this time employing Dudley Craven to build the amplifiers, who doubled the number of output valves used, along with using a larger power transformer and an extra output transformer. Around four of these amplifiers were built and delivered to Pete Townshend, and then the design was updated to form the now recognized SLP100 amplifier.

At this time, the KT66 valve was becoming more expensive, as the MOV Company faced greater competition from Mullard. Hence, another valve change was made, with Marshall starting to use European-made Mullard EL34 power stage valves. [3] These have a different overdrive character than the KT66's, which gave Marshalls a more aggressive voice still. In 1966, Marshall's most famous customer made his first appearance in England, and quickly found himself in Jim's shop. A young James Marshall Hendrix was in Jim's shop with his manager, Chas Chandler, trying the amplifiers and guitars. Jim Marshall was suspicious of Hendrix at first, expecting him to be "another American wanting something for nothing" but to his surprise, Hendrix offered to buy the amplifiers outright, if Jim would provide him with support for them around the world [4]. Jim Marshall agreed, and several of Hendrix's road crew were trained in the repair and maintenance of the Marshall amps through the years.

The amplifiers from this era, are easily identifiable by their acrylic glass (a.k.a. Plexiglas) (a.k.a. Perspex in the UK) front panel, which earned them the nickname, "Plexi"s. These now have significant collectors' value. Amplifiers from the 1970s onwards can be distinguished most easily by their brushed metal front panel, and are known as "ali panel" Marshalls. After 1973, in order to "streamline" production, the inefficient hand wiring was discontinued and all Marshall valve amplifiers were switched to printed circuit board paths. The result is a similar sound that some enthusiasts dub as more "sterile" sounding although this is a hotly debated topic within the musician community. Also, much of the tonal debate between the plexi and aluminum panel Marshall amps comes from the fact that in 1974 Marshall's US distributor had them change all of the amps sold in the US and Japan over to the much more rugged 6550 instead of the EL34 output tube. This produced a much different sound than the EL34 a sound that's less smooth and more metallic when overdriven. This change was brought about due to reliability problems with the EL34's and the 6550 generally allowed the amps to make it through warranty without problems. The circuit changes required to switch the amps are very minor and it's easy to change from the 6550 to the EL34 or vice versa by changing a few resistor values, moving the tap for the feedback loop and rebiasing the amp. The "mystique" surrounding the Plexi series only increased due to the roar first heard on Van Halen's 1978 eponymous debut.

In the mid-1970s, Marshall introduced the "master volume" ("MV") series, which was initially called the "JMP," not to be confused with the pre-amp made in the 1990s by Marshall. This was in response to the demand for yet more distortion, and many techs had been modifying the amps for years by connecting the two input stages in series rather than parallel as in the original Marshalls. A master volume was introduced to make the volume levels more manageable. This gave the new breed of Marshalls a different voice, more cutting and edgy, which later found favour with players such as Zakk Wylde, Randy Rhoads, and Slash. In the late 70s, Marshall began calling this series the "JCM800" series, and marketed two separate power levels, the 50 watt 2204 and the 100-watt 2203. Because the valve industry had begun to fade and Marshall became worried that the standard power valve, the venerable EL34 would soon become unavailable, a number of JCM 800s were factory equipped with the 6550 beam pentode power valve, a valve that contained a completely different tonal character. Some people (notably Ozzy Osbourne guitarist Zakk Wylde) loved the resulting sound, but it was generally considered to be a downgrade in sound quality. The 6550 is a high power tube that is most common in valve-driven bass amplifiers due to the fact that it does not distort even at extreme volume levels and because it has a very crisp low and high end sound. Because most players desired more power amp distortion (which is consider more "pleasant" than pre-amp distortion, which these Marshalls still had plenty of), the prices for EL34s, especially vintage ones, skyrocketed for use in Marshalls. Marshall would not return to full time use of the EL34 in all of its valve amps until the rise of vacuum tube factories in the mid and late 90s in former Soviet countries made most valve types plentiful again.

As time moved on, Marshall began to see more competition from American amplifier companies such as Mesa Boogie and Soldano, a number of which were based on "hot-rodded" Marshalls. Marshall then updated the JCM800 range with additional models and new features such as "channel switching," which meant that players could switch between clean and distorted tones with the push of a foot operated switch. This feature debuted in the 2205 series and these amps contained more pre-amp gain than ever thanks to a new innovation; diode clipping. This meant a solid state diode added additional distortion to the signal path, akin to adding a distortion pedal. While hotly criticised today among valve purists, these amps were more popular than ever, finding mass acceptance within the hard rock community and still in use today by many. Marshall around this time began further experiments with solid-state amplifiers, which were increasingly improving in quality due to technological innovations, but were still considered beginner level equipment. Regardless, solid state product lines with the Marshall name on them were and still are a wild (if critically discounted) success for the company, allowing the entry level guitarist to play the same brand of amp as his or her heroes.

In the 1990s, Marshall updated its product line again with the JCM900 series. Reviewed by Guitarist magazine in the UK and given the line, "Shredders, here is an amp you won't need to have modified," this move by Marshall was again an outgrowth of musicians' desires, featuring more distortion than ever and retaining popular aspects of the late JCM800 models. Around this time, Marshall released a few "special edition" amps in this range, including a "Slash Signature" model, a first for the company, and the Silver Jubilee and SL-X series (which added an additional pre-amp ECC83/12AX7 instead of diode-based distortion). Although the EL34 had at this time begun to return to prominence, a number of these were shipped with 5881 valves, a now uncommon valve similar in tone and build to a 6L6. However, Marshall acceptance was beginning to stagnate as users flocked to a number of available amplifiers.

Marshall currently produces a number of amplifiers which are a mix of modern designs and vintage reissues. Most models attempt to include the "classic" Marshall "roar."

Marshall's most recent entry in the JCM valve range was the JCM 2000 series of amplifiers, were started in the late 90s to replace the aging JCM 900 amplifiers, as Marshall had seemingly lost ground in the hard rock/metal amp market, particularly against Mesa/Boogie's wildly popular "Rectifier" series. The first two models launched were the DSL ("Dual Super Lead") 50 and 100 amplifier heads ("50" for 50 watts [powered by 2 EL34 power tubes] and "100" for 100 watts [powered by 4 EL34 power tubes]), and included the now modern FX Loop and reverb units. The reason for the success of these amplifiers was the fact that they arguably combined versatility, affordability, and 100% all tube tone into one package. Although many artists thrived on these amplifiers, others complained that Marshall sacrificed quality for versatility. The DSL featured two channels, one Clean and one Ultra (distorted) channel. They later introduced the TSL, this had a Crunch channel, which had less pre-amp distortion than the Ultra channel but was not quite clean either.

In 2007 Marshall released a new flagship line of UK-built amplifiers. After what many considered a "slump" period in which the company released nothing new and simply rehashed old models, Marshall finally came out with a new comprehensive range of amplifiers, the "JVM" series. Guitarist Magazine UK has already claimed that the JVM410 would be the "hottest" amp for 2007; they also hailed it as "The Ultimate Marshall."[2] JVM is an acronym for Jim Victoria Marshall, Victoria being his daughter and current managing director of Marshall Amplification.

The JVM series consists of a number of models, the flagship being the 100 watt JVM410. The JVM410 has four independent channels, Clean, Crunch, OD1 and OD2 and is available as a head or a combo unit. The other models in the range are the 100 watt JVM210, the 50 watt JVM205 and the 50 watt JVM215. These models have two independent channels consisting of Clean/Crunch and Overdrive channels. On all models each channel has its own set of tone, gain, volume and reverb controls and a master section consisting of dual master volumes, presence and resonance controls. The channels also have three different gain settings; by pressing the channel selection button repeatedly, the amplifier will change from green to orange to red while increasing the gain of the channel. This effectively gives the JVM410 12 independently-voiced modes which run from completely clean to ultra saturated modern metal and lead tones. The range of amplifiers have almost every modern feature including an effects loop, preamp out/in, silent record mode, fully programmable footswitch, Marshalls DI out they are also MIDI controller-ready. The 100 watt JVM uses four EL34 power valves in a "push-pull" configuration while the 50 watt uses two. The preamp utilizes five ECC83 preamp valves and offers a pure valve signal path even the reverb drive and recover circuit is valve driven, a single MOSFET has been used in the resonance circuit.

The Vintage Modern series is a brand new range for 2007. They are all-valve amplifiers aimed at the guitarist who likes control via playing/picking dynamics, and the guitar's own volume and tone controls. These amplifiers have a tone reminiscent of the mid 60s to early 70s vintage blues rock tone, with the ability to switch to a hot rod mode to find the "modded" tones of the harder rock bands of that era. Their wide range of tones is also derived from having two preamp volumes instead of one. Bascially one volume for treble, and one volume for bass/mid that when used together can customise a players tone and sound in a very simple yet precise way.

The models in the range are the 2466 100W head, the 2266 50W head and the 2266C 2x12” combo. All three models are all-valve with a choice of two ‘Dynamic ranges’ that are selectable via a footswitch. The low range equates to a stock vintage Marshall in terms of gain and tone, the high channel adds one extra gain stage to accommodate classic hard rock tones of the seventies. The units also have a ‘Mid Boost’ function that fattens the tone even more. The 2466 uses a quad of KT66 power valves while the 2266 uses a pair, these are reminiscent of the earliest Marshall amplifiers. The power supply and output stage has been taken directly from plexi amplifiers of the 1966 to 1968 era. The KT66 yields a much fatter and smoother tone than the EL34 and are inherently less aggressive in the treble region, the sound is instantly recognisable as early classic Marshall tone.

Marshall periodically will discontinue a model of amplifier, and reissue it later. Currently, the majority of Marshall's valve amp lineup are reissues. In 2001 Marshall reissued many of its amplifiers of yesteryears. The most popular and well known of these is the Model 1959-SLP, which is designed to be a reissue of the late 60s era "Plexi" amplifier, but which are in reality reissues of the post-1973 Super Lead models in that they use printed circuit boards internally for ease of production. The original design utilized hand wired circuits on turret boards, which is now available for a premium in the "hand wired" series. The actual difference in sound between the circuit paths is debatable, with some insisting PCB design is inferior and others (including Randall Smith of Mesa/Boogie) saying that the difference is negligible. Other reissues are similarly PCB designed, even where the originals were hand wired, with the except where explicitly noted (i.e. the "hand wired" range currently offered). Other models in the Vintage series include the 1987x (the 50W version of the 100w 1959SLP, used by some, including Yngwie Malmsteen for its lower headroom and "early" distortion curve), the 100 watt valve driven JCM800 2203 (used extensively by Zakk Wylde, Slash of Guns N' Roses and Velvet Revolver, used his signature model 2555 SL, as well as the Silver Jubilee 2555 variant of the series, and both Jeff Hanneman and Kerry King of Slayer), the JCM900 4100, the JTM45 2245, and the 1962 combo, also known as the "Bluesbreaker" for its famous use by Eric Clapton with John Mayall's Bluesbreakers.

Marshall has also recently introduced a handful of hand-wired reissues, using old-fashioned manufacturing techniques whereby the circuit is hand mounted on "turret boards." These have small metal stakes to which the components and leads are soldered, as compared to PCB, wherein the components are print-mounted by computer to the board, leads placed through the board, and soldered in place. The amps are "true" reissues of the 100 Watt 1959 "Plexi" a 20-Watt 2061x, and a 1974x 18-Watt model, which is a combo amp. The cabinet marketed as the match to the head version, as well as the combo, use special Celestion re-issued 55 Hz version of the popular "greenback" speaker, which Celestion has made available under its "Heritage" series.

While renowned for their valve guitar amps, Marshall produces and sells a large amount of solid state and bass equipment. Marshall's Valvestate amplifiers were at the time seen as evolutionary, as they contained a hybrid of valve and solid state technology, to provide a modicum of "true" valve tone, along with transistor reliability and ease of maintenance. Currently named the "AVT series", there are a number of different models, all of which are cheaper than their all-valve counterparts. It is Marshall's current line of "hybrid" amplifier, featuring a 12AX7 preamp tube employed in the preamp (to "warm up" the signal) as well as solid state components, with a solid-state power amp. The single valve featured in the valvestate amps can last from two to three years with standard use. These are considered and marketed as intermediate-level equipment to bridge the gap between the higher valve range and lower range MG series. Some feel they offer a quality and sound close to Marshall's higher end equipment. These amps are well known in the metal music community for their quick response time (known as "tightness").

The MG series is the currently produced fully solid state amplifiers, and are marketed towards beginners, players seeking a practice amp and those on a budget. The MG series is designed to cater for beginner to intermediate players, also gaining popularity as a convenient solution for smaller gigs. Though still marketed as offering the signature Marshall sound, it is not of the same quality of sound as Marshall's tube-powered models. The MG series of amplifiers have a switchable "Frequency Dependent-Dampening" system which emulates the way in which a valve amplifier interacts with the speaker(s). The series also offers a wealth of in-built functionality (including a handful of effects), which renders the MG series a notable competitor with other amps on the market; as well as producers of standalone guitar effects processors. Regardless of its majority appeal to lesser-fortuned musicians, former Rob Zombie guitarist Riggs was famous for using the MG series both live and in studio as he favored the Marshallesque sound combined with the reliability and quick response times associated with solid state amps, while Wayne Static of Static X is known for using the a 100 watt MG Head.

Although Marshall Amplification is well known for its guitar amplifiers and speaker cabinets, it also produces bass amplifiers. Marshall currently manufactures a professional, all-valve bass rig called the VBA400. It houses no less than eight 6550 power valves plus three ECC83 and one ECC82 preamp valves. The controls have been kept to a minimum and consist of a 3-band passive EQ network for Bass, Middle and Treble, which can be totally reconfigured by the means of a 3-position contour switch. Further tone control is provided by Deep and Bright switches. The input accommodates both Active and Passive bass pickups; there is also an XLR DI output for recording complete with Earth (grounding) lift and Pre/Post EQ switches. There is also a series FX loop, a tuner mute and a speed control for the fan that cools the power valves.

Two extension cabinets are available for the VBA, a 4x12” and an 8x10”. These cabinets have separate sealed chambers inside to prevent unwanted cabinet resonance and also add structural integrity. Both cabinets are loaded with custom design loudspeakers and give a total impedance of 4 ohms, the amplifier will drive loads of 2 ohms.

Other bass equipment currently available is the new MB range of amplifiers. The range consists of the MB15 (15 watt combo), MB30 (30 watt combo), MB60 (60 watt combo), MB150C (150 watt combo), MB4210C (450 watt 2x10” combo), MB4410 (450 watt 4x10” combo), MB450H (450 watt head) and three extension cabinets the MBC115 (1x15”), MBC410 (4x10”) and the MBC810 (8x10”). These units are mostly solid state, but have a single ECC83 preamp valve incorporated into the preamp, except in the MB15 and MB30 models.

Much confusion has arisen over the years due to Marshall's arbitrary method of naming each amp model, especially during its first few decades. For example, the models given the 1987 designation (in the late 1960s to 1970s), or the 1987x designation (in the 1990s and beyond) had nothing to do with the year 1987 nor was there any apparent relationship in the numbering to its direct counterpart the 1959 model, which was not made in 1959 either. This led to a "clean up" of the model numbering beginning with the JCM 2000 series, although reissues retain the original model numbers.

The classic Marshall Stack is one of the defining images behind loud rock music. A full stack consists of one head containing the actual amplifier, on top of two stacked 4x12s, which are loudspeaker cabinets each containing four 12 inch loudspeakers arranged in a square layout. The top cabinet has the top two loudspeakers angled slightly upwards, giving the Marshall stack a distinctive appearance. When a single cabinet is used, the complete unit is called a half stack.

In the early-mid 1960s, Pete Townshend and John Entwistle of The Who were directly responsible for the creation and widespread use of stacked Marshall cabinets. Pete later remarked that John started using Marshall Stacks in order to hear himself over Keith Moon's drums and Townshend himself also had to use them just to be heard over John. In fact, the very first 100 watt Marshall Amps were created specifically for Entwistle and Townshend when they were looking to replace some equipment that had been stolen from them. They approached Jim Marshall asking if it would be possible for him to make their new rigs more powerful than those they had lost, to which they were told that the cabinets would have to double in size. They agreed and six rigs of this prototype were manufactured, of which two each were given to Townshend and Entwistle and one each to Ronnie Lane and Steve Marriott of The Small Faces. These new "double" cabinets (each containing 8 speakers) proved too heavy and awkward to be transported practically, so The Who returned to Marshall asking if they could be cut in half and stacked, and although the double cabinets were left intact, the existing single cabinet models (each containing 4 speakers) were modified for stacking, which has become the norm for years to follow.^[2]

Entwistle and Townshend both continued expanding and experimenting with their rigs, until (at a time when most bands still used 50 to 100W amps with single cabinets) they were both using twin Stacks, with each Stack powered by new experimental prototype 200W amps, each connected to the guitar via a Y-splitter. This, in turn, also had a strong influence on the band's contemporaries at the time, with Cream and The Jimi Hendrix Experience both following suit. However, due to the cost of transport, The Who could not afford to take their full rigs with them for their earliest overseas tours, thus Cream and Hendrix were the first to be seen to use this setup on a wide scale, particularly in America. Ironically, although The Who pioneered and directly contributed to the development of the "classic" Marshall sound and setup with their equipment being built/tweaked to their personal specifications, they would only use Marshalls for a couple of years before moving on to using Sound City equipment. Cream, and particularly Hendrix, would be widely (and incorrectly) credited with the invention of Marshall Stacks.

The search for volume was taken on its next logical step with the advent of "daisy chaining" two or more amplifiers together. As most amplifier channels have two inputs, the guitar signal being present on both sockets, the cunning musician hooked the spare input of one channel to an input on another amp. By 1969 Hendrix was daisy chaining four Stacks, incorporating both Marshall and Sound City amplifiers, as recommended to him by Townshend.^[3]

This competition for greater volume and greater extremes was taken even further in the early 1970s by the band Blue Öyster Cult, which used an entire wall of full-stack Marshall Amplifiers as their backdrop. Bands such as Slayer and Yngwie Malmsteen also use walls of Marshalls. Both Kerry King and Jeff Hanneman of Slayer can be seen playing in front of a total of 24 cabinets, and Yngwie has used as many as 31. However, it is usually the case that far less are actually powered, as using this many could cause serious problems with the overall sound mix of a live show. In most cases these are "dummy cabs," which are onstage for visual impact, not actually played through. For ease of transportation and lifting, most of these actually do not even contain any speakers. The same goes for some of the amp heads in a scenario like this, as they are just the wooden frame with, in fact, no heavy inner workings.

Such is the ubiquity of the sight of a wall of Marshalls at a rock concert; many artists who do not even use them have the dummy stacks on stage. Rick Parfitt of Status Quo, for example has a wall of Marshalls, but actually uses a combination of Vox AC-30 in Marshall cabinets and JCM900's.^{[citation needed]}

Marshall also produces "combo" amplifiers, which combine speaker and amp in one case; and several variations of the classic stack design including a Marshall micro stack and a mini stack, the latter of which is a transistor practice amp about 10 inches high which runs on batteries.

• Marshall is based in Bletchley, Milton Keynes. It is currently the shirt sponsor of Milton Keynes Dons F.C. and sponsors Marshall Milton Keynes Athletic Club as well as Marshall Milton Keynes Lions basketball Club.^[4]
• The spoof 'rockumentary' This is Spinal Tap features a modified Marshall amplifier with panels specially prepared by Marshall with a volume dial that went up to eleven. Occasionally, Marshall releases amps which really do go to "11" as a reference.
• With the introduction of the JCM900 series, Marshall numbered the Lead Gain Control up to 20. Posters were produced featuring Spinal Tap guitarist Nigel Tufnel pointing to the control saying "Now it goes up to '20'. That's 9 louder, innit!"^[5]
• Some bands, including Motörhead, modify the "Marshall" logo on the front of Marshall Amplifiers to read "Moshall," "Marsha," or "Al." Alister Parker of Bailter Space covered up part of his to say "Mars." Lars Frederiksen of Rancid altered his to read "Lars". One of the guitarists for the band Maylene and the Sons of Disaster rotated and removed letters on his amplifier in order to spell "War yall."^{[citation needed]} On Nirvana's Bleach tour, they rearranged the logo to "Mash all". Metallica has a cab that reads "Asshole". Bands with an anti-corporate stance, such as Fugazi and Drive Like Jehu, have removed the logos entirely or covered them in black tape.
• The letters JTM, JVM and JCM derive from the initials of Terry (his son), Victoria (his daughter and current Managing Director) and James Charles (Jim's Christian names); JMP stands for Jim Marshall Products.
• Pure Digital, a maker of DAB Digital Audio Broadcasting radios, makes a model in the image of a Marshall amp, known as the Evoke-1XT Marshall Edition DAB digital radio.

• The Who's influence on sound

1. ^ http://www.premierguitar.com/archive/interviews/jim_marshall.htm
2. ^ The Who's Marshall History
3. ^ An interview with Pete Townshend from Guitarist magazine, August 1994
4. ^ http://www.miltonkeynestoday.co.uk/ViewArticle2.aspx?SectionID=416&ArticleID=2050730
5. ^ See the JCM 900 users manual available at the official Marshall Amps site listed below.

• Official Site
• Online Marshall and vintage "Plexi" community
• Oldest Marshall Amp site on the web
• Site with Lots of Marshall Photos
• Some Pictures from inside a Marshall JCM 900 Combo
• Marshall Amplification at Harmony Central
• Online Marshall Comunity